As the profile of the U.S. population dramatically changes, new data are necessary to support policy decisions. Monitoring the mental health status of ethnic and racial minorities is essential if actions to mitigate ethnic/racial disparities in health and health care use are to be based on empirical findings. The lack of quality data for Latinos and Asian Americans make it difficult to develop coherent public policies needed to develop prevention and treatment programs appropriate for these populations. The proposed research, the National Latino and Asian American Study (NLAAS), aims to provide national information on the similarities and differences in mental illness and service use of Latinos and Asian Americans, as compared to non-Latino whites and African Americans. The NLAAS would be the most comprehensive study of Latinos and Asian Americans ever conducted using up-to-date scientific strategies in the design, sampling procedures, psychiatric assessments, and analytic techniques. The NLAAS proposes to: (a) estimate the lifetime and 12 month prevalence of psychiatric disorders and the rates of mental health services use for Latino and Asian American populations; (b) estimate the association of social position, environmental context, and psychosocial factors with mental disorders and service use among Latinos and Asian Americans; and (c) compare the rates of psychiatric disorders and utilization of mental health services of Latinos and Asian Americans with national representative samples of non-Latino whites (from the National Survey of Health and Stress; NSHS-R) and African Americans (from the National Survey of African Americans; NSAA). To meet the aims, the investigators will interview 4,000 Latino (Puerto Ricans, Mexican Americans, Cubans, and Other Latinos) and 4,000 Asian American respondents (Chinese, Vietnamese, Filipinos, and Other Asians) across the U.S. Data collection will take place at the same time as the National Survey of Health and Stress Replication and the National Survey of African Americans during the spring of 2001. Accordingly, we expect to be able to provide important baseline data for Latinos and Asians that will be useful for examining whether the U.S. has diminished mental health disparities by the year 2010 (Healthy People 2010).